Transcranial Doppler sonography: adding to the toolbox.

rely on indirect evidence of nodal metastases. These include nodal enlargement, three or more borderline–sized nodes in a primary drainage pathway, and a nodal morphology showing a change from an elliptical to a spherical shape. The development of accurate radiologic criteria is important since 25% or more of patients presenting with head and neck cancer and no clinically palpable neck disease (stage N0 necks) harbor metastatic deposits in their cervical lymph nodes. While many of these metastatic deposits may be detected by imaging,